/*

 * Licensed to the Apache Software Foundation (ASF) under one or more

 * contributor license agreements.  See the NOTICE file distributed with

 * this work for additional information regarding copyright ownership.

 * The ASF licenses this file to You under the Apache License, Version 2.0

 * (the "License"); you may not use this file except in compliance with

 * the License.  You may obtain a copy of the License at

 * 

 *      http://www.apache.org/licenses/LICENSE-2.0

 * 

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

/*

 * $Id: MemBufInputSource.hpp 568078 2007-08-21 11:43:25Z amassari $

 */

#if !defined(MEMBUFINPUTSOURCE_HPP)

#define MEMBUFINPUTSOURCE_HPP

#include <xercesc/sax/InputSource.hpp>

XERCES_CPP_NAMESPACE_BEGIN

class BinInputStream;

/**

 *  This class is a derivative of the standard InputSource class. It provides

 *  for the parser access to data stored in a memory buffer. The type of

 *  buffer and its host specific attributes are of little concern here. The

 *  only real requirement is that the memory be readable by the current

 *  process.

 *

 *  Note that the memory buffer size is expressed in <b>bytes</b>, not in

 *  characters. If you pass it text data, you must account for the bytes

 *  per character when indicating the buffer size.

 *

 *  As with all InputSource derivatives. The primary objective of an input

 *  source is to create an input stream via which the parser can spool in

 *  data from the referenced source. In this case, there are two options

 *  available.

 *

 *  The passed buffer can be adopted or merely referenced. If it is adopted,

 *  then it must be dynamically allocated and will be destroyed when the

 *  input source is destroyed (no reference counting!.) If not adopted, the

 *  caller must insure that it remains valid until the input source object

 *  is destroyed.

 *

 *  The other option indicates whether each stream created for this input

 *  source should get its own copy of the data, or whether it should just

 *  stream the data directly from this object's copy of the data. The same

 *  rules apply here, in that the buffer must either be copied by the

 *  stream or it must remain valid until the stream is destroyed.

 */

class XMLPARSER_EXPORT MemBufInputSource : public InputSource

{

public :

    // -----------------------------------------------------------------------

    //  Constructors and Destructor

    // -----------------------------------------------------------------------

    /** @name Constructors */

    //@{

    /**

      * A memory buffer input source is constructed from a buffer of byte

      * data, and the count of bytes in that buffer. The parser will parse

      * from this memory buffer until it has eaten the indicated number of

      * bytes.

      *

      * Note that the system id provided serves two purposes. Firstly it is

      * going to be displayed in error messages as the source of the error.

      * And secondly, any entities which are refered to from this entity

      * via relative paths/URLs will be relative to this fake system id.

      *

      * @param  srcDocBytes     The actual data buffer to be parsed from.

      * @param  byteCount       The count of bytes (not characters, bytes!)

      *                         in the buffer.

      * @param  bufId           A fake system id for the buffer.

      * @param  adoptBuffer     Indicates whether this object should adopt

      *                         the buffer (i.e. become responsible for 

      * deletion) or just

      *                         use it in place.

      * @param  manager         Pointer to the memory manager to be used to

      *                         allocate objects.

      */

    MemBufInputSource

    (

        const   XMLByte* const  srcDocBytes

        , const unsigned int    byteCount

        , const XMLCh* const    bufId

        , const bool            adoptBuffer = false

        , MemoryManager* const  manager = XMLPlatformUtils::fgMemoryManager

    );

    /**

      * This constructor is identical to the previous one, except that it takes

      * the fake system id in local code page form and transcodes it internally.

      */

    MemBufInputSource

    (

        const   XMLByte* const  srcDocBytes

        , const unsigned int    byteCount

        , const char* const     bufId

        , const bool            adoptBuffer = false

        , MemoryManager* const  manager = XMLPlatformUtils::fgMemoryManager

    );

    //@}

    /** @name Destructor */

    //@{

    /**

      * If the buffer was adopted, the copy made during construction is deleted

      * at this point.

      */

    ~MemBufInputSource();

    //@}

    // -----------------------------------------------------------------------

    //  Virtual input source interface

    // -----------------------------------------------------------------------

    /** @name Virtual methods */

    //@{

    /**

      * This method will return a binary input stream derivative that will

      * parse from the memory buffer. If setCopyBufToStream() has been set,

      * then the stream will make its own copy. Otherwise, it will use the

      * buffer as is (in which case it must remain valid until the stream

      * is no longer in use, i.e. the parse completes.)

      *

      * @return A dynamically allocated binary input stream derivative that

      *         can parse from the memory buffer.

      */

    BinInputStream* makeStream() const;

    //@}

    // -----------------------------------------------------------------------

    //  Setter methods

    // -----------------------------------------------------------------------

    /** @name Setter methods */

    //@{

    /**

      * By default, for safety's sake, each newly created stream from this

      * input source will make its own copy of the buffer to stream from. This

      * avoids having to deal with aliasing of the buffer for simple work. But,

      * for higher performance applications or for large buffers, this is

      * obviously not optimal.

      *

      * In such cases, you can call this method to turn off that default

      * action. Once turned off, the streams will just get a pointer to the

      * buffer and parse directly from that. In this case, you must insure that

      * the buffer remains valid for as long as any parse events are still

      * using it.

      *

      * @param  newState    The new boolean flag state to set.

      */

    void setCopyBufToStream(const bool newState);

    /**

      * This methods allows the MemBufInputSource to be used for more than

      * one input source, instead of destructing/constructing another

      * MemBufInputSource.

      *

      * @param  srcDocBytes     The actual data buffer to be parsed from.

      * @param  byteCount       The count of bytes (not characters, bytes!)

      *                         in the buffer.     

      */

    void resetMemBufInputSource(const   XMLByte* const  srcDocBytes

                                , const unsigned int    byteCount);

    //@}

private :

    // -----------------------------------------------------------------------

    //  Unimplemented constructors and operators

    // -----------------------------------------------------------------------

    MemBufInputSource(const MemBufInputSource&);

    MemBufInputSource& operator=(const MemBufInputSource&);

    // -----------------------------------------------------------------------

    //  Private data members

    //

    //  fAdopted

    //      Indicates whether the buffer is adopted or not. If so, then it

    //      is destroyed when the input source is destroyed.

    //

    //  fByteCount

    //      The size of the source document.

    //

    //  fCopyBufToStream

    //      This defaults to true (the safe option), which causes it to

    //      give a copy of the buffer to any streams it creates. If you set

    //      it to false, it will allow the streams to just reference the

    //      buffer (in which case this input source must stay alive as long

    //      as the buffer is in use by the stream.)

    //

    //  fSrcBytes

    //      The source memory buffer that is being spooled from. Whether it

    //      belongs to the this input source or not is controlled by the

    //      fAdopted flag.

    // -----------------------------------------------------------------------

    bool            fAdopted;

    unsigned int    fByteCount;

    bool            fCopyBufToStream;

    const XMLByte*  fSrcBytes;

};

inline void MemBufInputSource::setCopyBufToStream(const bool newState)

{

    fCopyBufToStream = newState;

}

XERCES_CPP_NAMESPACE_END

#endif